method Deferred.prototype.thenimport { Deferred } from "https://deno.land/x/steam_trader@v0.4.0/src/deferred.ts"; then<TResult1 = T, TResult2 = never>(onfulfilled?: ((value: T) => TResult1 | PromiseLike<TResult1>) | undefined | null, onrejected?: ((reason: any) => TResult2 | PromiseLike<TResult2>) | undefined | null): Promise<TResult1 | TResult2>Type ParametersoptionalTResult1 = ToptionalTResult2 = neverParametersoptionalonfulfilled: ((value: T) => TResult1 | PromiseLike<TResult1>) | undefined | nulloptionalonrejected: ((reason: any) => TResult2 | PromiseLike<TResult2>) | undefined | nullReturnsPromise<TResult1 | TResult2>